Sometimes for reference purposes, one needs to duplicate a paragraph (X) to paragraph Y, one can easily by copy paste, but in case he/she wants to modify Y and want that modification (or in that case every modification) to be reflected in X, he/she will have to copy-paste every time to update. A feasible solution will be to 'clone' Y to X, that way if one changes X or Y, both of the paragraphs will be changed. A cloned paragraph will be specified by a non-printable gray colored border which can be toggled on or off. The navigator will have a list of cloned paragraphs.
sounds interesting
Reproducible with LO 5.2.1.2 32bit (win10 Ent 64bit)